Centering means for phonographic records and the like.



B. M. HANSEN. CENTERING MEANS FOR PHONOGRAPHIC RECORDS AND THE LIKE.

APPLICATION man Aue.21. I916- L w fimu Patented Jan.15, 1918.

RTE M. HANSEN, 018 SAN FNCISCO, CALIFORNIA.

CENTING MEANS FOR PHONOGRAPHIC REGQEDS AND THE LIKE.

Specification of Letteru Eatcnt.

Patented Jan. 115, ildllh.

application filed August 21, 1916. Serial lilo. 116,202.

To all whom it may concern."

Be it known that I, BERTRAM M. Hansen, a citizen of the United States,residing in the city and county of San Francisco and State ofCalifornia, have invented a new and useful Improvement in CenteringMeans for Phonographic ltecords and the like, of which the following isa specification.

My invention relates to. improved center bearings for phonographicrecords and the like wherein the aperture is brought concentric with theapproximately concentric sound convolutions; and the objects of myinvention are:

First, to provide an improved central bearing for phonographi'c recordsand the like that shall be adapted to resist wear and thereby preventthe enlargement of the record aperture whereby the alinement of thesound convolutions to the axis of rotation may be preserved.

Second, to provide an improved central bearing or centering meanswhereby the central aperture of the record may be valined or arrangedapproximately concentric with the sound convolutions of the record.

Third, to provide improved means adapt-' ed to reduce the frictionalengagement of a reproducing needle with the record and thereby improvethe harmony of the selection being rendered.

Fourth, to provide improved means whereby the wear on the sound orimpression convolutions or grooves may be eliminated.

T accomplish these and other objects by means of the devicedisclosed inthe drawings forming a part of the present specification wherein likecharacters of reference are used to designate similar parts throughoutthe said specification and drawings, and in which- Figure 1 is a planview of a phonographic record disclosing my invention applied thereto.

Fig. 2 is an enlarged broken transverse sectional view of a recorddisclosing more fully in detail the construction and arrangement of mvinvention.

Referring to the drawings the numeral 1 is used to designate aphonographic record having the usual sound impressions or convolutions 2arranged approximately con-' centric with said record 1. Notwithstandingthat the said convolutions 2 are spiral, being continuous, the termconcentric is applied thereto in an illustrative sense for the reasonthat the pitch of said spirals is so small in' proportion to thediameter of the disk 1 that said convolutions 2 may be said to beapproximately concentric.

The disk 1 is provided with the usual approximately central aperture 3which is provided by the simple process of boring or punchmg through theapproximate center of the disk 1.

In practice it seems to be a rather difficult matter to form theaperture 3 absolutely central to the convolutions 2 and the result isthat when the record 1 is rotated for reproducing, the reproducingneedle, not shown, instead of having a constant speed in one direction,viz.: toward the center of the disk as is the practice, that a waveringor approximately reciprocating movement is imparted to the needle andbox with the result that the said needle is forced alternatelyagainstopposite sides of the V-shaped sound convolutions or grooves 2thereby producing an undue friction which tends to increase the hissingor metallic sound which is generally magnified by the reproducer to thedetriment of the harmony of the selection being rendered.

T eliminate or reduce this friction and thereby not only improve theharmon of the selection being rendered but also e imi- Late the wear onthe sides of the convolutions 2 and also the aperture through the softermaterial of the record by means of the metallic centering means whichmay be described as follows:

. Washers 4 are arranged on each side of the record 1 and adjacent tothe aperture 3 therein. These washers 4 may be arranged on the top ofthe record 1 as disclosed in the upper central portion of Fig. 2 of thedrawings, or the record adjacent the said aperture 3 may be countersunkso that the said washers may lie flush with the surface of the record 1as disclosed in the lower central portion of the figure referred to.

A metallic gromet or sleeve 6 is provided with annular flanges 7 and 8,the flange 8 I being larger in diameter than the flange 7 and arrangedto engage the outer surface of the lower washer 4 in Fig. 2 of thedrawings. The smaller flange 7 of the gromet or sleeve 6 is engaged by athird washer 9 provided for the purpose of providing greater stabilityto the entire construction when assembled.

Before the smaller annular flange '3' is Mid Mil

spun, punched or otherwise impressed onto the third washer 9 the boresleeve 6 is alined.

concentric with the convolutions 2 of the disk 1, thereby eliminatingthe wavering motion which tends to increase the frictiona engagement ofthe reproducin needle, thereby eliminating wear on the side of thegroove.

When said alinement has been accomplished in any suitable manner theflange 7 of the gromet or sleeve 6 is tightly impressed onto the thirdwasher 9 so as to tightly and rigidly secure the entire structure to thedisk 1 thereby retaining said alinement.

It is obvious from the foregoing that I have provided an improvedcentering means for phonographic records and t e like wherein theharmony of the selection may be improved as well as means wherebywearing of the centering aperture and grooves may be prevented. I amaware that the present state of the art discloses gromets of variousdesigns applied to various uses; I do 'not therefore claim the broadprinciple of the gromet, but what I do claim as new and desire to secureby Letters Patent is The combination with a centrally aperturedphonographic record having the usual convolutions thereon, of a metallicgromet comprising a circular washer arranged on each side of the record;a metallic sleeve having-an annular flange on each end thereof one ofsaid flanges being of larger diameter than the other and arranged toengage one of the washers; and a third washer arranged to engage theremaining washer and to be in turn engaged by the smaller flange on theendof the sleeve whereby said sleeve ma be secured within the centralaperture 31 kconcentric with the convolutions of the 1s i In witnesswhereof I hereunto set my signature. 1 V

BERTBAM M. HANSEN.

